1 /* 2 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/parallelScavenge/adjoiningGenerations.hpp" 27 #include "gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp" 28 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp" 29 #include "gc_implementation/parallelScavenge/gcTaskManager.hpp" 30 #include "gc_implementation/parallelScavenge/generationSizer.hpp" 31 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp" 32 #include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp" 33 #include "gc_implementation/parallelScavenge/psMarkSweep.hpp" 34 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp" 35 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp" 36 #include "gc_implementation/parallelScavenge/psScavenge.hpp" 37 #include "gc_implementation/parallelScavenge/vmPSOperations.hpp" 38 #include "memory/gcLocker.inline.hpp" 39 #include "oops/oop.inline.hpp" 40 #include "runtime/handles.inline.hpp" 41 #include "runtime/java.hpp" 42 #include "runtime/vmThread.hpp" 43 #include "services/memTracker.hpp" 44 #include "utilities/vmError.hpp" 45 46 PSYoungGen* ParallelScavengeHeap::_young_gen = NULL; 47 PSOldGen* ParallelScavengeHeap::_old_gen = NULL; 48 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL; 49 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL; 50 ParallelScavengeHeap* ParallelScavengeHeap::_psh = NULL; 51 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL; 52 53 static void trace_gen_sizes(const char* const str, 54 size_t og_min, size_t og_max, 55 size_t yg_min, size_t yg_max) 56 { 57 if (TracePageSizes) { 58 tty->print_cr("%s: " SIZE_FORMAT "," SIZE_FORMAT " " 59 SIZE_FORMAT "," SIZE_FORMAT " " 60 SIZE_FORMAT, 61 str, 62 og_min / K, og_max / K, 63 yg_min / K, yg_max / K, 64 (og_max + yg_max) / K); 65 } 66 } 67 68 jint ParallelScavengeHeap::initialize() { 69 CollectedHeap::pre_initialize(); 70 71 // Cannot be initialized until after the flags are parsed 72 // GenerationSizer flag_parser; 73 _collector_policy = new GenerationSizer(); 74 75 size_t yg_min_size = _collector_policy->min_young_gen_size(); 76 size_t yg_max_size = _collector_policy->max_young_gen_size(); 77 size_t og_min_size = _collector_policy->min_old_gen_size(); 78 size_t og_max_size = _collector_policy->max_old_gen_size(); 79 80 trace_gen_sizes("ps heap raw", 81 og_min_size, og_max_size, 82 yg_min_size, yg_max_size); 83 84 const size_t og_page_sz = os::page_size_for_region(yg_min_size + og_min_size, 85 yg_max_size + og_max_size, 86 8); 87 88 const size_t og_align = set_alignment(_old_gen_alignment, og_page_sz); 89 const size_t yg_align = set_alignment(_young_gen_alignment, og_page_sz); 90 91 // Update sizes to reflect the selected page size(s). 92 // 93 // NEEDS_CLEANUP. The default TwoGenerationCollectorPolicy uses NewRatio; it 94 // should check UseAdaptiveSizePolicy. Changes from generationSizer could 95 // move to the common code. 96 yg_min_size = align_size_up(yg_min_size, yg_align); 97 yg_max_size = align_size_up(yg_max_size, yg_align); 98 size_t yg_cur_size = 99 align_size_up(_collector_policy->young_gen_size(), yg_align); 100 yg_cur_size = MAX2(yg_cur_size, yg_min_size); 101 102 og_min_size = align_size_up(og_min_size, og_align); 103 // Align old gen size down to preserve specified heap size. 104 assert(og_align == yg_align, "sanity"); 105 og_max_size = align_size_down(og_max_size, og_align); 106 og_max_size = MAX2(og_max_size, og_min_size); 107 size_t og_cur_size = 108 align_size_down(_collector_policy->old_gen_size(), og_align); 109 og_cur_size = MAX2(og_cur_size, og_min_size); 110 111 trace_gen_sizes("ps heap rnd", 112 og_min_size, og_max_size, 113 yg_min_size, yg_max_size); 114 115 const size_t heap_size = og_max_size + yg_max_size; 116 117 ReservedSpace heap_rs = Universe::reserve_heap(heap_size, og_align); 118 119 MemTracker::record_virtual_memory_type((address)heap_rs.base(), mtJavaHeap); 120 121 os::trace_page_sizes("ps main", og_min_size + yg_min_size, 122 og_max_size + yg_max_size, og_page_sz, 123 heap_rs.base(), 124 heap_rs.size()); 125 if (!heap_rs.is_reserved()) { 126 vm_shutdown_during_initialization( 127 "Could not reserve enough space for object heap"); 128 return JNI_ENOMEM; 129 } 130 131 _reserved = MemRegion((HeapWord*)heap_rs.base(), 132 (HeapWord*)(heap_rs.base() + heap_rs.size())); 133 134 CardTableExtension* const barrier_set = new CardTableExtension(_reserved, 3); 135 _barrier_set = barrier_set; 136 oopDesc::set_bs(_barrier_set); 137 if (_barrier_set == NULL) { 138 vm_shutdown_during_initialization( 139 "Could not reserve enough space for barrier set"); 140 return JNI_ENOMEM; 141 } 142 143 // Initial young gen size is 4 Mb 144 // 145 // XXX - what about flag_parser.young_gen_size()? 146 const size_t init_young_size = align_size_up(4 * M, yg_align); 147 yg_cur_size = MAX2(MIN2(init_young_size, yg_max_size), yg_cur_size); 148 149 // Make up the generations 150 // Calculate the maximum size that a generation can grow. This 151 // includes growth into the other generation. Note that the 152 // parameter _max_gen_size is kept as the maximum 153 // size of the generation as the boundaries currently stand. 154 // _max_gen_size is still used as that value. 155 double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0; 156 double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0; 157 158 _gens = new AdjoiningGenerations(heap_rs, 159 og_cur_size, 160 og_min_size, 161 og_max_size, 162 yg_cur_size, 163 yg_min_size, 164 yg_max_size, 165 yg_align); 166 167 _old_gen = _gens->old_gen(); 168 _young_gen = _gens->young_gen(); 169 170 const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes(); 171 const size_t old_capacity = _old_gen->capacity_in_bytes(); 172 const size_t initial_promo_size = MIN2(eden_capacity, old_capacity); 173 _size_policy = 174 new PSAdaptiveSizePolicy(eden_capacity, 175 initial_promo_size, 176 young_gen()->to_space()->capacity_in_bytes(), 177 intra_heap_alignment(), 178 max_gc_pause_sec, 179 max_gc_minor_pause_sec, 180 GCTimeRatio 181 ); 182 183 assert(!UseAdaptiveGCBoundary || 184 (old_gen()->virtual_space()->high_boundary() == 185 young_gen()->virtual_space()->low_boundary()), 186 "Boundaries must meet"); 187 // initialize the policy counters - 2 collectors, 3 generations 188 _gc_policy_counters = 189 new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _size_policy); 190 _psh = this; 191 192 // Set up the GCTaskManager 193 _gc_task_manager = GCTaskManager::create(ParallelGCThreads); 194 195 if (UseParallelOldGC && !PSParallelCompact::initialize()) { 196 return JNI_ENOMEM; 197 } 198 199 return JNI_OK; 200 } 201 202 void ParallelScavengeHeap::post_initialize() { 203 // Need to init the tenuring threshold 204 PSScavenge::initialize(); 205 if (UseParallelOldGC) { 206 PSParallelCompact::post_initialize(); 207 } else { 208 PSMarkSweep::initialize(); 209 } 210 PSPromotionManager::initialize(); 211 } 212 213 void ParallelScavengeHeap::update_counters() { 214 young_gen()->update_counters(); 215 old_gen()->update_counters(); 216 MetaspaceCounters::update_performance_counters(); 217 } 218 219 size_t ParallelScavengeHeap::capacity() const { 220 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes(); 221 return value; 222 } 223 224 size_t ParallelScavengeHeap::used() const { 225 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes(); 226 return value; 227 } 228 229 bool ParallelScavengeHeap::is_maximal_no_gc() const { 230 return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc(); 231 } 232 233 234 size_t ParallelScavengeHeap::max_capacity() const { 235 size_t estimated = reserved_region().byte_size(); 236 if (UseAdaptiveSizePolicy) { 237 estimated -= _size_policy->max_survivor_size(young_gen()->max_size()); 238 } else { 239 estimated -= young_gen()->to_space()->capacity_in_bytes(); 240 } 241 return MAX2(estimated, capacity()); 242 } 243 244 bool ParallelScavengeHeap::is_in(const void* p) const { 245 if (young_gen()->is_in(p)) { 246 return true; 247 } 248 249 if (old_gen()->is_in(p)) { 250 return true; 251 } 252 253 return false; 254 } 255 256 bool ParallelScavengeHeap::is_in_reserved(const void* p) const { 257 if (young_gen()->is_in_reserved(p)) { 258 return true; 259 } 260 261 if (old_gen()->is_in_reserved(p)) { 262 return true; 263 } 264 265 return false; 266 } 267 268 bool ParallelScavengeHeap::is_scavengable(const void* addr) { 269 return is_in_young((oop)addr); 270 } 271 272 #ifdef ASSERT 273 // Don't implement this by using is_in_young(). This method is used 274 // in some cases to check that is_in_young() is correct. 275 bool ParallelScavengeHeap::is_in_partial_collection(const void *p) { 276 assert(is_in_reserved(p) || p == NULL, 277 "Does not work if address is non-null and outside of the heap"); 278 // The order of the generations is old (low addr), young (high addr) 279 return p >= old_gen()->reserved().end(); 280 } 281 #endif 282 283 // There are two levels of allocation policy here. 284 // 285 // When an allocation request fails, the requesting thread must invoke a VM 286 // operation, transfer control to the VM thread, and await the results of a 287 // garbage collection. That is quite expensive, and we should avoid doing it 288 // multiple times if possible. 289 // 290 // To accomplish this, we have a basic allocation policy, and also a 291 // failed allocation policy. 292 // 293 // The basic allocation policy controls how you allocate memory without 294 // attempting garbage collection. It is okay to grab locks and 295 // expand the heap, if that can be done without coming to a safepoint. 296 // It is likely that the basic allocation policy will not be very 297 // aggressive. 298 // 299 // The failed allocation policy is invoked from the VM thread after 300 // the basic allocation policy is unable to satisfy a mem_allocate 301 // request. This policy needs to cover the entire range of collection, 302 // heap expansion, and out-of-memory conditions. It should make every 303 // attempt to allocate the requested memory. 304 305 // Basic allocation policy. Should never be called at a safepoint, or 306 // from the VM thread. 307 // 308 // This method must handle cases where many mem_allocate requests fail 309 // simultaneously. When that happens, only one VM operation will succeed, 310 // and the rest will not be executed. For that reason, this method loops 311 // during failed allocation attempts. If the java heap becomes exhausted, 312 // we rely on the size_policy object to force a bail out. 313 HeapWord* ParallelScavengeHeap::mem_allocate( 314 size_t size, 315 bool* gc_overhead_limit_was_exceeded) { 316 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint"); 317 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread"); 318 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); 319 320 // In general gc_overhead_limit_was_exceeded should be false so 321 // set it so here and reset it to true only if the gc time 322 // limit is being exceeded as checked below. 323 *gc_overhead_limit_was_exceeded = false; 324 325 HeapWord* result = young_gen()->allocate(size); 326 327 uint loop_count = 0; 328 uint gc_count = 0; 329 int gclocker_stalled_count = 0; 330 331 while (result == NULL) { 332 // We don't want to have multiple collections for a single filled generation. 333 // To prevent this, each thread tracks the total_collections() value, and if 334 // the count has changed, does not do a new collection. 335 // 336 // The collection count must be read only while holding the heap lock. VM 337 // operations also hold the heap lock during collections. There is a lock 338 // contention case where thread A blocks waiting on the Heap_lock, while 339 // thread B is holding it doing a collection. When thread A gets the lock, 340 // the collection count has already changed. To prevent duplicate collections, 341 // The policy MUST attempt allocations during the same period it reads the 342 // total_collections() value! 343 { 344 MutexLocker ml(Heap_lock); 345 gc_count = Universe::heap()->total_collections(); 346 347 result = young_gen()->allocate(size); 348 if (result != NULL) { 349 return result; 350 } 351 352 // If certain conditions hold, try allocating from the old gen. 353 result = mem_allocate_old_gen(size); 354 if (result != NULL) { 355 return result; 356 } 357 358 if (gclocker_stalled_count > GCLockerRetryAllocationCount) { 359 return NULL; 360 } 361 362 // Failed to allocate without a gc. 363 if (GC_locker::is_active_and_needs_gc()) { 364 // If this thread is not in a jni critical section, we stall 365 // the requestor until the critical section has cleared and 366 // GC allowed. When the critical section clears, a GC is 367 // initiated by the last thread exiting the critical section; so 368 // we retry the allocation sequence from the beginning of the loop, 369 // rather than causing more, now probably unnecessary, GC attempts. 370 JavaThread* jthr = JavaThread::current(); 371 if (!jthr->in_critical()) { 372 MutexUnlocker mul(Heap_lock); 373 GC_locker::stall_until_clear(); 374 gclocker_stalled_count += 1; 375 continue; 376 } else { 377 if (CheckJNICalls) { 378 fatal("Possible deadlock due to allocating while" 379 " in jni critical section"); 380 } 381 return NULL; 382 } 383 } 384 } 385 386 if (result == NULL) { 387 // Generate a VM operation 388 VM_ParallelGCFailedAllocation op(size, gc_count); 389 VMThread::execute(&op); 390 391 // Did the VM operation execute? If so, return the result directly. 392 // This prevents us from looping until time out on requests that can 393 // not be satisfied. 394 if (op.prologue_succeeded()) { 395 assert(Universe::heap()->is_in_or_null(op.result()), 396 "result not in heap"); 397 398 // If GC was locked out during VM operation then retry allocation 399 // and/or stall as necessary. 400 if (op.gc_locked()) { 401 assert(op.result() == NULL, "must be NULL if gc_locked() is true"); 402 continue; // retry and/or stall as necessary 403 } 404 405 // Exit the loop if the gc time limit has been exceeded. 406 // The allocation must have failed above ("result" guarding 407 // this path is NULL) and the most recent collection has exceeded the 408 // gc overhead limit (although enough may have been collected to 409 // satisfy the allocation). Exit the loop so that an out-of-memory 410 // will be thrown (return a NULL ignoring the contents of 411 // op.result()), 412 // but clear gc_overhead_limit_exceeded so that the next collection 413 // starts with a clean slate (i.e., forgets about previous overhead 414 // excesses). Fill op.result() with a filler object so that the 415 // heap remains parsable. 416 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded(); 417 const bool softrefs_clear = collector_policy()->all_soft_refs_clear(); 418 419 if (limit_exceeded && softrefs_clear) { 420 *gc_overhead_limit_was_exceeded = true; 421 size_policy()->set_gc_overhead_limit_exceeded(false); 422 if (PrintGCDetails && Verbose) { 423 gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: " 424 "return NULL because gc_overhead_limit_exceeded is set"); 425 } 426 if (op.result() != NULL) { 427 CollectedHeap::fill_with_object(op.result(), size); 428 } 429 return NULL; 430 } 431 432 return op.result(); 433 } 434 } 435 436 // The policy object will prevent us from looping forever. If the 437 // time spent in gc crosses a threshold, we will bail out. 438 loop_count++; 439 if ((result == NULL) && (QueuedAllocationWarningCount > 0) && 440 (loop_count % QueuedAllocationWarningCount == 0)) { 441 warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t" 442 " size=%d", loop_count, size); 443 } 444 } 445 446 return result; 447 } 448 449 // A "death march" is a series of ultra-slow allocations in which a full gc is 450 // done before each allocation, and after the full gc the allocation still 451 // cannot be satisfied from the young gen. This routine detects that condition; 452 // it should be called after a full gc has been done and the allocation 453 // attempted from the young gen. The parameter 'addr' should be the result of 454 // that young gen allocation attempt. 455 void 456 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) { 457 if (addr != NULL) { 458 _death_march_count = 0; // death march has ended 459 } else if (_death_march_count == 0) { 460 if (should_alloc_in_eden(size)) { 461 _death_march_count = 1; // death march has started 462 } 463 } 464 } 465 466 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) { 467 if (!should_alloc_in_eden(size) || GC_locker::is_active_and_needs_gc()) { 468 // Size is too big for eden, or gc is locked out. 469 return old_gen()->allocate(size); 470 } 471 472 // If a "death march" is in progress, allocate from the old gen a limited 473 // number of times before doing a GC. 474 if (_death_march_count > 0) { 475 if (_death_march_count < 64) { 476 ++_death_march_count; 477 return old_gen()->allocate(size); 478 } else { 479 _death_march_count = 0; 480 } 481 } 482 return NULL; 483 } 484 485 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) { 486 if (UseParallelOldGC) { 487 // The do_full_collection() parameter clear_all_soft_refs 488 // is interpreted here as maximum_compaction which will 489 // cause SoftRefs to be cleared. 490 bool maximum_compaction = clear_all_soft_refs; 491 PSParallelCompact::invoke(maximum_compaction); 492 } else { 493 PSMarkSweep::invoke(clear_all_soft_refs); 494 } 495 } 496 497 // Failed allocation policy. Must be called from the VM thread, and 498 // only at a safepoint! Note that this method has policy for allocation 499 // flow, and NOT collection policy. So we do not check for gc collection 500 // time over limit here, that is the responsibility of the heap specific 501 // collection methods. This method decides where to attempt allocations, 502 // and when to attempt collections, but no collection specific policy. 503 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) { 504 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); 505 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); 506 assert(!Universe::heap()->is_gc_active(), "not reentrant"); 507 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); 508 509 // We assume that allocation in eden will fail unless we collect. 510 511 // First level allocation failure, scavenge and allocate in young gen. 512 GCCauseSetter gccs(this, GCCause::_allocation_failure); 513 const bool invoked_full_gc = PSScavenge::invoke(); 514 HeapWord* result = young_gen()->allocate(size); 515 516 // Second level allocation failure. 517 // Mark sweep and allocate in young generation. 518 if (result == NULL && !invoked_full_gc) { 519 do_full_collection(false); 520 result = young_gen()->allocate(size); 521 } 522 523 death_march_check(result, size); 524 525 // Third level allocation failure. 526 // After mark sweep and young generation allocation failure, 527 // allocate in old generation. 528 if (result == NULL) { 529 result = old_gen()->allocate(size); 530 } 531 532 // Fourth level allocation failure. We're running out of memory. 533 // More complete mark sweep and allocate in young generation. 534 if (result == NULL) { 535 do_full_collection(true); 536 result = young_gen()->allocate(size); 537 } 538 539 // Fifth level allocation failure. 540 // After more complete mark sweep, allocate in old generation. 541 if (result == NULL) { 542 result = old_gen()->allocate(size); 543 } 544 545 return result; 546 } 547 548 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) { 549 CollectedHeap::ensure_parsability(retire_tlabs); 550 young_gen()->eden_space()->ensure_parsability(); 551 } 552 553 size_t ParallelScavengeHeap::unsafe_max_alloc() { 554 return young_gen()->eden_space()->free_in_bytes(); 555 } 556 557 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const { 558 return young_gen()->eden_space()->tlab_capacity(thr); 559 } 560 561 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const { 562 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr); 563 } 564 565 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) { 566 return young_gen()->allocate(size); 567 } 568 569 void ParallelScavengeHeap::accumulate_statistics_all_tlabs() { 570 CollectedHeap::accumulate_statistics_all_tlabs(); 571 } 572 573 void ParallelScavengeHeap::resize_all_tlabs() { 574 CollectedHeap::resize_all_tlabs(); 575 } 576 577 bool ParallelScavengeHeap::can_elide_initializing_store_barrier(oop new_obj) { 578 // We don't need barriers for stores to objects in the 579 // young gen and, a fortiori, for initializing stores to 580 // objects therein. 581 return is_in_young(new_obj); 582 } 583 584 // This method is used by System.gc() and JVMTI. 585 void ParallelScavengeHeap::collect(GCCause::Cause cause) { 586 assert(!Heap_lock->owned_by_self(), 587 "this thread should not own the Heap_lock"); 588 589 unsigned int gc_count = 0; 590 unsigned int full_gc_count = 0; 591 { 592 MutexLocker ml(Heap_lock); 593 // This value is guarded by the Heap_lock 594 gc_count = Universe::heap()->total_collections(); 595 full_gc_count = Universe::heap()->total_full_collections(); 596 } 597 598 VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause); 599 VMThread::execute(&op); 600 } 601 602 void ParallelScavengeHeap::oop_iterate(ExtendedOopClosure* cl) { 603 Unimplemented(); 604 } 605 606 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) { 607 young_gen()->object_iterate(cl); 608 old_gen()->object_iterate(cl); 609 } 610 611 612 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const { 613 if (young_gen()->is_in_reserved(addr)) { 614 assert(young_gen()->is_in(addr), 615 "addr should be in allocated part of young gen"); 616 // called from os::print_location by find or VMError 617 if (Debugging || VMError::fatal_error_in_progress()) return NULL; 618 Unimplemented(); 619 } else if (old_gen()->is_in_reserved(addr)) { 620 assert(old_gen()->is_in(addr), 621 "addr should be in allocated part of old gen"); 622 return old_gen()->start_array()->object_start((HeapWord*)addr); 623 } 624 return 0; 625 } 626 627 size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const { 628 return oop(addr)->size(); 629 } 630 631 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const { 632 return block_start(addr) == addr; 633 } 634 635 jlong ParallelScavengeHeap::millis_since_last_gc() { 636 return UseParallelOldGC ? 637 PSParallelCompact::millis_since_last_gc() : 638 PSMarkSweep::millis_since_last_gc(); 639 } 640 641 void ParallelScavengeHeap::prepare_for_verify() { 642 ensure_parsability(false); // no need to retire TLABs for verification 643 } 644 645 void ParallelScavengeHeap::print_on(outputStream* st) const { 646 young_gen()->print_on(st); 647 old_gen()->print_on(st); 648 MetaspaceAux::print_on(st); 649 } 650 651 void ParallelScavengeHeap::print_on_error(outputStream* st) const { 652 this->CollectedHeap::print_on_error(st); 653 654 if (UseParallelOldGC) { 655 st->cr(); 656 PSParallelCompact::print_on_error(st); 657 } 658 } 659 660 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const { 661 PSScavenge::gc_task_manager()->threads_do(tc); 662 } 663 664 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const { 665 PSScavenge::gc_task_manager()->print_threads_on(st); 666 } 667 668 void ParallelScavengeHeap::print_tracing_info() const { 669 if (TraceGen0Time) { 670 double time = PSScavenge::accumulated_time()->seconds(); 671 tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time); 672 } 673 if (TraceGen1Time) { 674 double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds(); 675 tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time); 676 } 677 } 678 679 680 void ParallelScavengeHeap::verify(bool silent, VerifyOption option /* ignored */) { 681 // Why do we need the total_collections()-filter below? 682 if (total_collections() > 0) { 683 if (!silent) { 684 gclog_or_tty->print("tenured "); 685 } 686 old_gen()->verify(); 687 688 if (!silent) { 689 gclog_or_tty->print("eden "); 690 } 691 young_gen()->verify(); 692 } 693 } 694 695 void ParallelScavengeHeap::print_heap_change(size_t prev_used) { 696 if (PrintGCDetails && Verbose) { 697 gclog_or_tty->print(" " SIZE_FORMAT 698 "->" SIZE_FORMAT 699 "(" SIZE_FORMAT ")", 700 prev_used, used(), capacity()); 701 } else { 702 gclog_or_tty->print(" " SIZE_FORMAT "K" 703 "->" SIZE_FORMAT "K" 704 "(" SIZE_FORMAT "K)", 705 prev_used / K, used() / K, capacity() / K); 706 } 707 } 708 709 ParallelScavengeHeap* ParallelScavengeHeap::heap() { 710 assert(_psh != NULL, "Uninitialized access to ParallelScavengeHeap::heap()"); 711 assert(_psh->kind() == CollectedHeap::ParallelScavengeHeap, "not a parallel scavenge heap"); 712 return _psh; 713 } 714 715 // Before delegating the resize to the young generation, 716 // the reserved space for the young and old generations 717 // may be changed to accomodate the desired resize. 718 void ParallelScavengeHeap::resize_young_gen(size_t eden_size, 719 size_t survivor_size) { 720 if (UseAdaptiveGCBoundary) { 721 if (size_policy()->bytes_absorbed_from_eden() != 0) { 722 size_policy()->reset_bytes_absorbed_from_eden(); 723 return; // The generation changed size already. 724 } 725 gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size); 726 } 727 728 // Delegate the resize to the generation. 729 _young_gen->resize(eden_size, survivor_size); 730 } 731 732 // Before delegating the resize to the old generation, 733 // the reserved space for the young and old generations 734 // may be changed to accomodate the desired resize. 735 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) { 736 if (UseAdaptiveGCBoundary) { 737 if (size_policy()->bytes_absorbed_from_eden() != 0) { 738 size_policy()->reset_bytes_absorbed_from_eden(); 739 return; // The generation changed size already. 740 } 741 gens()->adjust_boundary_for_old_gen_needs(desired_free_space); 742 } 743 744 // Delegate the resize to the generation. 745 _old_gen->resize(desired_free_space); 746 } 747 748 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() { 749 // nothing particular 750 } 751 752 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() { 753 // nothing particular 754 } 755 756 #ifndef PRODUCT 757 void ParallelScavengeHeap::record_gen_tops_before_GC() { 758 if (ZapUnusedHeapArea) { 759 young_gen()->record_spaces_top(); 760 old_gen()->record_spaces_top(); 761 } 762 } 763 764 void ParallelScavengeHeap::gen_mangle_unused_area() { 765 if (ZapUnusedHeapArea) { 766 young_gen()->eden_space()->mangle_unused_area(); 767 young_gen()->to_space()->mangle_unused_area(); 768 young_gen()->from_space()->mangle_unused_area(); 769 old_gen()->object_space()->mangle_unused_area(); 770 } 771 } 772 #endif